Manual Motor Protectors; Through 575V Only); Discharge Line Thermostat; Unit Description - Trane RAUJ-C20 Installation, Operation And Maintenance Manual

G G e e n n e e r r a a l l I I n n f f o o r r m m a a t t i i o o n n
the 115V control circuit. If no faults are observed, a
green LED will be energized.
Manual Motor Protectors (380V through
575V Only)
Manual motor protectors will be used as branch circuit
protection for compressors. These devices are capable
of providing both overload and short-circuit protection.
Before operating, the manual motor protector must be
switched with the rotary on/off switch to the "ON"
position and the overload setpoint dial must be set to
the appropriate rating of the motor.
I I m m p p o o r r t t a a n n t t : : In order to avoid nuisance trips, the
overload setpoint dial must be adjusted to
the following calculated value:
Overload Setting = (Compressor RLA) x
1.12
Figure 1. Compressor protection module
The 80 to 120 ton CSHN compressors include a
preinstalled motor protection module mounted and
wired into the compressor terminal box. This device
provides protection against the following:
• Overcurrent caused by overloading (sensed by
motor temperature)
• Overheating of the motor
• Phase loss/reversal
• Phase sequence
The motor protector includes a motor protection
module and Positive Temperature Coefficient
thermistors (PTC) embedded in the motor windings.
The close contact between the thermistors and
windings ensures a very low level of thermal inertia.
10

Discharge Line Thermostat

The first compressor on each circuit is equipped with a
Discharge Line Thermostat. If the temperature of the
line exceeds 230°F the thermostat interrupts the 115V
control circuit for the compressors and all the
compressors on the circuit will de-energize. Once the
temperature drops below 180°F the thermostat will
close and allow the compressor to be energized.

Unit Description

All air cooled condensing units are designed for
outdoor installations with vertical air discharge. These
units may be installed on a flat roof or placed on a
concrete slab at ground level.
Before shipment, each unit is leak-tested, evacuated, a
nitrogen holding charge is added, and the controls are
tested for proper operation.
The condenser coils are all-aluminum microchannel
design. Corrosion protected condenser coils are a
standard option. Louvered condenser grilles for coil
protection are standard. Direct-drive, vertical discharge
condenser fans are provided with built-in current and
overload protection.
For "Ship with" items, see the following figures.
If low ambient operation is required, low ambient
dampers are available as a field or factory installed
option.
Units may be ordered with one of the following
options:
• No System Controls (Field provided controls
required)
• Constant Volume Controls
• Supply Air Temperature Control (VAV applications)
• EVP Chiller Controls
Basic unit components include:
• Manifolded scroll compressors
• Condenser coils
• Condenser fans (number based on unit size)
• Discharge service valve (one per circuit)
• Liquid line service valve (one per circuit)
SS-SVX11K-EN